Stitchbonded, washable nonwoven towels and method for making

ABSTRACT

A stitchbonded washable towel made from a stitchbonded fabric having a cellulosic nonwoven sheet of cellulosic fibers, and an integrated nonwoven sheet of an outer sublayer of wood pulp fibers, and an inner layer of textile fibers substantially entangled with the wood pulp fibers, and confronting the cellulosic nonwoven sheet of cellulosic fibers. The stitchbonded fabric as uses a pattern of stitching yarns that fixes the cellulosic nonwoven sheet to the integrated nonwoven sheet. A post-treatment of the stitchbonded fabric in a heated aqueous solution containing soil release polymer gathers the fabric into the towel, and provides stain and soil re-deposition resistance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.16/383,047, filed Apr. 12, 2019, which claims the benefit of U.S.Provisional Application No. 62/657,418, filed Apr. 13, 2018, thedisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Stitchbonded nonwoven fabric is made by multi-needle stitching of afibrous layer with one or more stitching thread systems to form patternsof stitches in the layer. Known processes for making a stitchbondednonwoven fabric typically include the steps of (a) feeding a fibrouslayer to a stitchbonding machine; (b) threading a multi-needle bar ofthe stitchbonding machine with stitching threads; (c) inserting thestitching threads into the fibrous layer to form a pattern of spacedapart, interconnected rows of stitches, thereby creating thestitchbonded fabric; (d) removing the stitchbonded fabric from thestitchbonding machine; and (e) optionally subjecting the stitchbondedfabric to further textile finishing operations, such as shrinking, heatsetting, molding, coating, impregnating and the like.

In a process of stitch bonding fabrics, a multiplicity of stitchingyarns is passed repeatedly in stitching relation through one or moresubstrate layers in closely spaced rows, so as to form a coordinatedarrangement of surface stitches in covering relation to the substrate.It is possible to use such stitchbonding techniques to formsubstantially uniform surfaces covered by the stitching yarns. It isalso possible to impart patterns of stitching yarns across the surfaceby manipulation of the formation process. Such patterns may usesubstantially flat stitches, or optionally upstanding loops, orcombinations thereof.

Stitchbonded nonwoven fabrics using stitching threads of fully drawn,flat and uncrimped crystalline polymeric yarns (also called “hardyarns”) are known. Although the use of stitching threads of such yarnshas been quite successful in many stitchbonded fabrics, such fabricsnonetheless have certain shortcomings. For example, such stitchbondedfabrics, although dimensionally stable, usually perform inadequately inmolding or thermoforming operations, and also tend to unravel from thecut edges of a fabric, if they are submitted to washing or drying orrough handling.

Stitchbonded fabrics can also use textured bulkable yarns, typically ofa polymeric material, containing filaments that have been drawn and setto cause or force the yarns to develop elastic spring-like crimp, asthey shrink relative to their length. When these yarns are stitched ontoa substrate while straightened under tension, and then the stitchedfabric is released from stitching, the stitched yarns tend to relaxback, re-develop the crimp, and in the cases of substrates that are thinor soft and easy to gather, they gather the stitched fabric, impartingbulk and a degree of elasticity to the stitched and gathered fabric.When the fabric is subjected to heat and/or humidity free of stress, asin the case of washing and drying, the textured bulkable yarns candevelop sufficient shrinking power to cause a stitched fabric usingrelatively thin or soft substrates to gather significantly and developrelatively high levels of elastic stretch. The textured/bulkable yarnsalso develop filament crimp in-situ, within the fabric, which helps tohold the yarns in-place and allows the stitched fabrics to be subjectedto multiple uses and multiple washings without unraveling.

Stitchbonded nonwoven fabrics can also include stitching threads ofspandex elastomeric elastic yarns, which are capable of elongating andcontracting in the range of 100 to 250%, allowing the production ofstitchbonded fabrics with still higher levels of gather and stretch. Theuse of textured/bulkable yarns, and the use elastomeric yarns with orwithout accompanying textured or flat non-elastomeric threads, isdisclosed in, for example, in U.S. Pat. Nos. 4,876,128, 4,773,238,4,737,394 and 4,704,321 for making bulky and/or stretchy stitchbondedfabrics, in WO 94/19523 for making abrasion-resistant resin-impregnatedstitchbonded fabrics, and in U.S. Pat. No. 5,308,674 for makingtear-resistant stitchbonded fabrics, the disclosures of which areincorporated by reference. According to the processes disclosed in thesepatents, the stitchbonded fabric, immediately upon removal from themulti-needle stitching operation may be allowed to shrink and gather anddevelop elastic stretch. The development of these properties can becontrolled by varying the yarn constructions and compositions, theweight and softness of the stitching substrates and the type of stitchesused in the process.

Stitchbonded nonwoven fabrics can also include stitching threads oryarns that consist essentially of fibers or filaments of partiallymolecularly-oriented synthetic organic polymer. U.S. Pat. No. 6,407,018,the disclosure of which is incorporated by reference, describes aprocess that includes feeding a nonwoven fiber layer to a stitchbondingmachine having at least one multi-needle stitching bar, threading aneedle bar with stitching thread, inserting a pattern of stitches withthe threaded multi-needle stitching bar into the nonwoven fiber layer toform the stitchbonded nonwoven fabric, and then optionally subjectingthe stitchbonded nonwoven fabric to shrink the partiallymolecularly-oriented yarn, and gather the nonwoven fabric.

In the industrial laundry industry, cotton towels are laundered andrented to customers for the cleaning of kitchens, tables, walls, bartops, and various other miscellaneous duties. The range of uses for thetowels creates an environment where the product is subjected to muchabuse. These towels are not ideal for all of these applications becauseof a lack of strength, propensity to lint, poor dimensional stability,and susceptibility to degradation from chlorine bleach. Degradation inthe presence of chlorine is a particular problem with the longevity ofthe products because US DHEC (Department of Health and EnvironmentalControl) regulations state that restaurants are required to soak theircleaning towels in a chlorine bleach solution for health reasons. Also,industrial laundries must bleach the towels heavily in the wash cycle toremove the tremendous loading of stains, grease, and particulate fromthe towels. For these reasons, the towels have a very short life spanand are not as durable as the laundries or restaurants would prefer. Thewear and abuse the towels endure also cause tears and holes in theproduct which is not desirable to restaurants and other customersbecause they look dirty and worn in front of their clients and project apoor image for the company.

US Publication 2007/0270071, the disclosure of which is incorporated byreference, teaches a nonwoven fabric towel containing 25 to 75% byweight a polyester or polyester co-polymer staple fiber having a staplelength of between 3 and 6 inches, and 25 to 50% by weight amulti-segment splitable staple fiber comprising a polyester or polyesterco-polymer component and a polyamide component. The nonwoven fabrictowel is bonded with stitches of a bulkable yarn. The polyester fibers,polyester co-polymer staple fibers, or the multi-segment splittablestaple fibers, have a hydrophilic surface treatment on the surfaces, toeffect some improvement water absorption of the nonwoven towel forsopping up spills.

Notwithstanding the advancements in the field, there remains a need fora washable nonwoven fabric towel with excellent absorbency, durability,and cleanability, while having good hand.

SUMMARY OF THE INVENTION

The present invention provides a composite stitchbonded fabric, and moreparticularly a composite nonwoven stitchbonded fabric, that can beprocessed into a stitchbonded towel, which can be used and washedrepeatedly under industrial laundering conditions, while retainingintegrity, durability and good hand.

In an embodiment of the invention, a composite stitchbonded fabriccomprises: a cellulosic nonwoven sheet comprising a nonwoven layer ofcellulosic fibers along a technical front of the composite stitchbondedfabric; an integrated nonwoven sheet comprising an outer sublayer ofwood pulp fibers and an inner sublayer of textile fibers, wherein thetextile fibers of the inner sublayer are entangled with the wood pulpfibers of the outer sublayer to form the integrated nonwoven sheet, theinner sublayer of textile fibers confronts the cellulosic nonwovensheet, and an outer surface of the outer sublayer of wood pulp fibers isalong a technical back of the composite stitchbonded fabric; and apattern of stitching yarns that fixes the cellulosic nonwoven sheet tothe integrated nonwoven sheet, comprising a plurality of yarn overlapson the technical front of the composite stitchbonded fabric, and aplurality of yarn underlaps on the technical back of the compositestitchbonded fabric.

In another embodiment, a composite stitchbonded fabric comprises a firstnonwoven sheet comprising a nonwoven layer of cellulosic fibers,selected from the group consisting of textile-grade continuouscellulosic filaments, staple-length cut cellulosic fibers, and acombination thereof, located along the technical front (also known asthe technical face) of the composite stitchbonded fabric, and anintegrated nonwoven sheet comprising a sublayer of wood pulp fibers, anda sublayer of textile fibers, wherein the wood pulp fiber sublayer andthe textile fiber sublayer of the integrated nonwoven sheet areinter-entangled to form an integrated nonwoven sheet structure. Theouter sublayer of wood pulp fibers is located along the technical backof the composite stitchbonded fabric, and the inner sublayer of textilefiber confronts the inside surface of the cellulosic nonwoven sheet. Thecomposite stitchbonded fabric uses one or more patterns of stitchingyarns using a single-bar or two-bar, or three-bar system, that fix ortie the cellulosic nonwoven sheet to the integrated nonwoven sheet.

Preferably the fabric is stitched with at least two bars. Alsopreferably the patterns of stitching yarns comprise at least one patternoriginating from a front-bar or a middle-bar or a back-bar, formingunderlap yarns (underlaps) that connect the rows or wales of stitches ina zig-zag pattern, and partially cover and protect the exposed wood pulpsublayer of the integrated nonwoven sheet on the technical back of thecomposite nonwoven fabric, while the overlap yarns (overlaps) formed bythe same bar and all other bars align within the parallel rows or walesof stitches exposed over the cellulosic nonwoven sheet along thetechnical front of the composite fabric. In selected embodiments, one ormore of the stitching bars may form a linear pattern, such as a “chain”or “pillar” stitch, wherein the underlaps stay within the wales, butserve to reinforce the composite or to interlock with the yarns of theother bars. In other selected embodiments, one or more of the knittingbars may simply “lay-in” in a flat zig/zag layer of underlaps betweenwales on the technical back, held down by other stitching bar yarns thatpenetrate through. The laid-in or stitched-in underlaps protect theouter wood pulp sublayer. The laid-in yarn does not show at all on thetechnical front.

In an embodiment of the invention, the cellulosic fibers of the firstnonwoven sheet can be selected from the group consisting of lyocell,rayon, and cotton, and other natural cellulosic materials, such as flax,hemp, jute, and ramie. In a further embodiment the cellulosic fibers arelyocell. Cotton and the other natural cellulosic fibers are provided inits natural staple form. The other cellulosic fibers, and particularlylyocell and rayon, can be in the form of textile-grade continuousfilaments, or staple-length cut fiber, or a combination thereof.

In an embodiment of the invention, the first nonwoven sheet furthercomprises up to about 75% wood pulp fibers, preferably blended-in orattached to the inner side of the first nonwoven sheet of the cellulosicfibers, to avoid the direct and unprotected exposure of such wood pulpfibers between the wales on the technical back of the compositestitchbonded fabric.

In an embodiment of the invention, the integrated nonwoven sheetcomprises a composite nonwoven sheet comprising a weight ratio of woodpulp fibers (in the outer sublayer) to textile fibers (in the innersublayer) between about 1:3 to about 3:1 for example, a weight ratio ofat least 1:2, for example, at least 1:1, and at least 2:1, and up toabout 2:1, for example, up to about 1:1, and up to about 1:2. Typically,the content of the wood pulp fibers in the integrated nonwoven sheet isabout 25-75% by weight, and the content of the textile fibers is about25-75% by weight.

In an embodiment of the invention, the textile fibers of the innersublayer of the integrated nonwoven sheet comprise polyester fibers. Inanother embodiment, the textile fibers of the inner sublayer compriselyocell fibers. In another embodiment, the textile fibers of the innersublayer comprise polylactic acid (PLA) or nylon fibers. In anotherembodiment, the textile fibers of the inner sublayer comprise acombination of two or more of polyester fibers, lyocell fibers, nylon,and PLA fibers.

In a non-limiting embodiment, a weight ratio of the polyester fibers,combined with other staple-length fibers, for example with lyocellfibers, or with PLA fibers, or with a combination of lyocell and PLAfibers, in the inner sublayer, is at least about 1:9, and up to about9:1, for example, at least about 1:5, at least about 1:3, and at leastabout 1:2, for example, about 1:1, and up to about 5:1, up to about 3:1,and up to about 2:1. In a further non-limiting embodiment, the weightratio of a combination of lyocell fibers and PLA fibers is at leastabout 1:9, and up to about 9:1, for example, at least about 1:5, atleast about 1:3, and at least about 1:2, for example, about 1:1, and upto about 5:1, up to about 3:1, and up to about 2:1.

In an embodiment of the invention, the composite stitchbonded fabric hasa cellulosic content of at least 25%, for example, at least 40%, atleast 50%, at least 60%, and at least 70%, of the total weight of thenonwoven layers and sheets, where the cellulosic content is comprisedfrom at least one or more of wood pulp fibers, lyocell fibers, PLAfibers, rayon fibers, and other cellulosic-based fibers. In anembodiment, the composite stitchbonded fabric has a high content ofcellulosic-containing fibers, and includes a preponderance ofcellulosic-containing fibers on the technical front and technical backof the stitchbonded fabric.

In a further embodiment of the invention, the composite stitchbondedfabric has a cellulosic content of at least 90%, for example, at least95%, and at least 98%, and up to 100%, of the total weight of thenonwoven layers and sheets.

In one embodiment, the integrated nonwoven sheet is made by combining aweb, sheet or layer comprising textile fibers, with a pre-formed layeror paper containing wood pulp fibers. The component fibers of wood pulpfibers and textile fibers are hydroentangled. In a particularembodiment, the web, sheet or layer comprising textile fibers is acontinuous-filament spunbond/spunmelt polyester, polypropylene or nylonnonwoven fabric.

In an embodiment of the invention, the composite stitchbonded fabricfurther includes a third sheet comprising textile fibers, disposedbetween the cellulosic nonwoven sheet and the integrated nonwoven sheet.The textile fibers of the third nonwoven sheet can comprise polyesterfibers, lyocell fibers, PLA fibers, nylon fiber, or natural cellulosicmaterials, such as cotton, flax, hemp, jute, and ramie fibers, or acombination thereof.

In a further embodiment of the invention, the stitchbonded fabric isformed into a towel-sized fabric unit. In another or optionalembodiment, the towel-sized fabric unit can include a stabilizedboundary region along at least a portion of the periphery, including theentirety of the periphery.

The present invention also comprises a method for making thestitchbonded composite fabric described herein above.

In one embodiment, a method for making a composite stitchbonded fabric,comprising the steps of: providing a cellulosic nonwoven sheetcomprising a nonwoven layer of textile cellulosic fibers; providing anintegrated nonwoven sheet comprising an outer sublayer of wood pulpfibers and an inner sublayer of textile fibers, wherein the textilefibers of the inner sublayer are entangled with the wood pulp fibers ofthe outer sublayer to form the integrated nonwoven sheet, with the innersublayer of textile fibers providing an inner surface of the integratednonwoven sheet; placing the cellulosic nonwoven sheet over the innersurface of the integrated nonwoven sheet; and stitching the cellulosicnonwoven sheet to the integrated nonwoven sheet, to form a linearpattern of overlap wales on a technical front of the compositestitchbonded fabric aligned with the cellulosic nonwoven sheet, and apattern of crisscrossing yarn underlaps on a technical back of thecomposite stitchbonded fabric aligned with the wood pulp sublayer of theouter sublayer of the integrated nonwoven sheet.

In another embodiment, a method for making a composite stitchbondedfabric comprises the steps of: a) providing a cellulosic nonwoven sheetcomprising a nonwoven sheet of cellulosic fibers; b) providing anintegrated nonwoven sheet comprising an outer sublayer of wood pulpfibers, and an inner sublayer of textile fibers defining an insidesurface, wherein the textile fibers of the inner layer and the wood pulpfibers of the outer sublayer are inter-entangled to form the integratednonwoven sheet, with the outer surface of the outer sublayer of the woodpulp fibers located along a technical back of the composite stitchbondedfabric; c) placing the cellulosic nonwoven sheet over the inner surfaceof the integrated nonwoven sheet; and d) stitching the cellulosicnonwoven sheet to the integrated nonwoven sheet, to form linear overlapsor wales on a technical front of the composite stitchbonded fabric, anda pattern of linear underlaps, or optionally linear and diagonalunderlaps, alternating across wales along the technical back of thecomposite stitchbonded fabric.

In an embodiment of the invention, the fibers of the inner sublayer ofthe integrated nonwoven sheet comprise polyester fibers. In anotherembodiment, the fibers of the inner sub-layer can alternatively compriselyocell fibers, or PLA fibers, or a combination of lyocell fibers, nylonfibers and PLA fibers. In another embodiment, the fibers of the innerlayer comprise combinations of polyester fibers and one or more oflyocell fibers, nylon fibers, and PLA fibers.

In an embodiment of the invention, the method further includes placing athird sheet comprising fibers, between the cellulosic nonwoven sheet andthe integrated nonwoven sheet, before stitching. The fibers of the thirdnonwoven layer can comprise one or a combination of polyester fibers,lyocell fibers, nylon fibers, and PLA fibers, or other polymers orcellulosic-containing fibers.

In an embodiment of the invention, the method further includes formingthe fabric into a plurality of towel-sized fabric units, and optionallyforming a stabilized boundary region along at least a portion of aperiphery or the entire periphery of the towel-sized fabricunits.

In an embodiment of the invention, the stitching yarn can comprise oneor more of a polyester yarn, a nylon yarn, a yarn of polylactic acid(PLA), a yarn of lyocell material, a yarn of other polymers, and acombination or mixture thereof.

In selected embodiments at least one of the knitting bars uses texturedbulkable yarns deployed under tension. These yarns relax in-situ withinthe stitched fabric, thereby developing spring-like crimp, and lockingthe stitches within the fabric. They furthermore tend to gather thefabric in one or two directions. The textured bulkable yarns can be usedexclusively or in combination with hard yarns or elastomeric yarns orpartially-oriented yarns.

In an embodiment of the invention, the front-bar yarn comprises nylonyarn, and the back-bar yarn comprises polyester yarn. Alternatively, thefront-bar yarn comprises polyester yarn, and the back-bar yarn comprisesnylon yarn.

In another embodiment, the front-bar yarn and/or the back-bar yarn cancomprise a partially-oriented or textured bulkable nylon yarn, and theback-bar yarn comprises a partially-oriented or textured bulkablepolyester yarn.

In an alternative embodiment, the front-bar yarn comprises apartially-oriented or textured bulkable polyester yarn, and the back-baryarn comprises a partially-oriented or textured bulkable nylon yarn.

In yet another embodiment, either the front- or the back-bar yarn, orboth front- and the back-bar yarn, can include a combination of yarnscomprising a polyester (or partially-oriented or textured bulkablepolyester) yarn and a yarn comprising nylon (or partially-oriented ortextured bulkable nylon) yarn.

In another embodiment, a portion of the front-bar yarn or the back-baryarn, or a portion of both the front-bar yarn and the back-bar yarn, cancomprise polylactic acid (PLA). The PLA yarn can be used in a partial ortotal replacement of a polyester yarn or nylon yarn, or both.

In another embodiment, a portion of the front-bar yarn or the back-baryarn, or a portion of both the front-bar yarn and the back-bar yarn, cancomprise lyocell yarn. The lyocell yarn can be used in a partial ortotal replacement of a polyester yarn or nylon yarn, or both.

In an embodiment of the invention, the method further includes apost-treatment of the plurality of towel-sized fabric units to form aplurality of stitchbonded washable towels, comprising the steps of: i)placing the towel-sized fabric units into a drum of a launderingapparatus; and ii) exposing the towel-sized fabric units to a heatedaqueous solution having a temperature less than a temperature at whichthe partially-oriented or textured or bulkable yarns, which may includenylon and polyester filaments, become fully fixed, for a period of timesufficient to effect shrinkage and gathering of the towel-sized fabricunits into stitchbonded washable towels.

In an embodiment of the invention, the heated aqueous solution has atemperature including and between about 125 and 200 degrees F. (52 and93 degrees C.), and in a further embodiment, a temperature including andbetween about 175 and 185 degrees F. (79 and 85 degrees C.).

In an embodiment of the invention, the time sufficient to effectshrinkage and gathering is from about 5 minutes to about one hour.

In an embodiment of the invention, the heated aqueous solution comprisesa soil release polymer, preferably at a level of about 0.05% to 3.0% byweight of the dry towel-sized fabric units. In a further embodiment, thesoil release polymer comprises Pomoco 5962.

The present invention also comprises a stitchbonded washable towel. Thetowel can comprise a gathered, cellulosic nonwoven sheet comprising anonwoven layer of cellulosic fibers along a front face of the towel, anda gathered, integrated nonwoven sheet comprising an outer sublayer ofwood pulp fibers and an inner sublayer of textile fibers that have beensubstantially entangled with the wood pulp fibers of the outer sublayer,to form an integrated nonwoven sheet, with the inner sublayer of textilefibers confronting the cellulosic nonwoven face sheet, and the outersublayer of the wood pulp fibers along a back face of the towel. Thecellulosic nonwoven sheet and the integrated nonwoven back sheet arefixed and gathered together by a multiplicity of stitching yarnscomprising a post-shrunken front-bar yarn and post-shrunken back-baryarn. The cellulosic fibers, the textile fibers, and the stitching yarnsare described herein above.

In an embodiment of the invention, the towel further includes a soilrelease polymer coated onto the surfaces of the fibers and the woodpulp.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a schematic illustration of an elongated sheet of astitchbonded nonwoven fabric, formed by overlaying two sheets ofnonwoven and stitchbonding the sheets together, showing the technicalfront of the fabric on top

FIG. 2 shows a schematic illustration of the fabric of FIG. 1 with thetechnical back of the fabric on top.

FIG. 3 illustrates a towel-size unit of the stitchbonded nonwoven fabricof FIGS. 1 and 2.

FIG. 4 illustrates a gathered stitchbonded towel formed after apost-treatment of the towel-size unit of FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION

Definitions:

As used herein, the terms “bulkable yarn”, “textured yarn”, “texturedbulkable yarn” and “shrinkable” each refer to a spring-like thread oryarn that can be stitched under tension, and, when released, it canshrink back and develop crimp, also causing the stitchbonded fabric tobe bulked or gathered by being deformed out-of-plane. The deformationproperty in a thread or yarn can be induced by well known means; onemeans includes releasing tension from the thread or yarn, or by exposingthe thread to chemical action, moisture and/or heat at a temperaturesufficient to cause shrinkage along the length, or width or both; forexample, a temperature of about 50 to 200° C.

As used herein, the terms “calender” or “calendering” refers to aprocess for imparting surface effects onto fabrics or nonwoven webs.Without intending to be limiting, a fabric or nonwoven web may becalendered by passing the fabric or nonwoven web through two or moreheavy rollers, sometimes heated, under high nip pressures.

As used herein, the terms “carding” or “carded web” refers to theprocess of opening and aligning staple fibers that are first formed as athin combed layer, and optionally formed into a cross-lapped bulky webor bulky batt to produce generally uniform basis weight.

As used herein, the phrase “cellulosic fibers” refers to bothtextile-grade continuous filaments and staple-length cut fibers, unlessmentioned or distinguished otherwise.

As used herein, the term “cross-lapped” means to spread a layer ofcombed loose fibers, or a warp of filaments or yarns, in a back andforth manner that is roughly transverse to the direction of theformation of the combed layer or warp, with the individual lapspartially overlapping each other such that they form an acute angle witheach other.

As used herein, a “filament” refers to a fiber that is formed into asubstantially continuous trand.

As used herein, the terms “hydroentangle” or “hydroentangling” refers toa process by which a high velocity waterjet is forced through a web offibers causing them to become randomly entangled. Hydroentanglement mayalso be used to impart images, patterns, or other surface effects to anonwoven fabric by, for example, hydroentangling the fibers on athree-dimensional image transfer device such as that disclosed in U.S.Pat. No. 5,098,764 to Bassett et al, or a foraminous member such as thatdisclosed in U.S. Pat. No. 5,895,623 to Trokhan et al., both fullyincorporated herein by reference.

As used herein, “needle punching” means to mechanically entangle a webof either non-bounded or loosely bounded fibers by passing barbedneedles through the fiber web.

As used herein, the term “nonwoven sheet” means a web having a structureof individual fibers, yarns, or threads which are interlaid, but not ina regular or identifiable manner as in a woven or knitted fabric.Nonwoven fabrics or webs can be formed from many processes such as, forexample, melt-blowing processes, spunbonding processes, air layingprocesses, and bonded carded web processes. Carded and needle-punchednonwoven webs are preferred for their good bulk and cushion. Thenonwoven sheet can include one or more individual layers, typicallybonded or integrated together.

As used herein, a “composite nonwoven fabric” means a fabric formed fromone or more nonwoven sheets or layers.

As used herein, a “staple fiber” means a fiber of finite length. Astaple fiber can be a natural fiber such as cotton, or a cut-fiberstarting as a filament. A cut staple length used to form textileproducts by weaving, knitting, stitchbonding, carding, or formingstaple-based “spun” yarns, is usually a “textile -grade staple” in therange of 3/8 to 5 inches (1 to 12.5 cm), more frequently in the range of½ to 4 inches (1.2 to 10 cm). Shorter staple fibers are used to formreinforced papers when mixed with pulps and processed with specialair-lay or wet-lay machines.

As used herein, the term “yarn” refers to a continuous, often plied,strand composed of either natural or man-made cut-staple fibers orman-made continuous filaments, used in weaving, knitting, stitchbonding,sewing, and other similar operations.

Composite Stitchbonded Fabric

Referring now to FIGS. 1 and 2, there is shown a composite stitchbondedfabric 10 that can be used as, for example, a cleaning towel. Thecomposite stitchbonded fabric 10 includes a cellulosic nonwoven sheet 20and an integrated nonwoven sheet 30. The cellulosic nonwoven sheet 20and the integrated nonwoven sheet 30 are overlapped and tied or attachedto each other with stitches of shrinkable yarns 40 comprising a patternof overlaps 50 along the technical front 16 of the fabric, and a patternof underlaps 60 on the wales along the technical back 18 of the fabricshown in FIG. 1. Some of the underlaps 60 bridge across the wales 70,while other underlaps 60 follow the wales depending upon the type ofstitching pattern selected for each stitching bar. Each of the underlapsand overlaps originate from the same yarn that penetrates though layers20 and 30, except for “laid-in” stitches that stay on the technical backside 18, held down by other yarns, originating from another bar, that gothrough both layers 20 and 30 along the wales 70.

The composite stitchbonded fabric 10 can be formed into a towel-sizedfabric unit 80, as shown in FIG. 3. The fabric unit 80 can be bondedtogether within a portion of a boundary region 82 at the periphery 84,in order to avoid fraying or tearing in subsequent use and repeatedlaundering. One or more of the four sides of the towel can bestabilized. Stabilization can be by means of stitching, such as serging,or by bonding by heat if the construction contains sufficientthermoplastic fiber content that can be heat fused. Fusing can beaccomplished by any means that imparts sufficient heat and pressure in alocalized area to create a durable bond. Processes such as hot pressfusing, ultrasonic fusing, radio frequency fusing, or other heat andpressure producing processes can be used. A preferred process uses heatfusing on the two ends of the towel unit that follow the cross-machinedirection from stitchbonding. Ultrasonic bonding is the preferredmethod.

The resulting stitchbonded washable towel 90 has excellent absorbencyand durability, and can have improved stain resistance, while havinggood hand. The towel-sized fabric unit 80 that can be further treated toform into a stitchbonded washable towel 90, as shown in FIG. 4.

The cellulosic nonwoven sheet 20 can comprise lyocell fibers. Lyocell isa manmade fiber derived from cellulose, better known in the UnitedStates under the brand name Tencel®. Though it is related to rayon,another cellulosic fabric, lyocell is created by a solvent spinningtechnique, and the cellulose undergoes no significant chemical change.In an embodiment of the invention, the cellulosic nonwoven sheet 20comprises about 75%-100% lyocell fibers, and optionally up to 25%, or upto 50%, or up to 75%, wood pulp fibers. A layer of lyocell fibers can beproduced using an air laid machine inline, a carding machine inline oroffline with prebonding via hydroentangling. The inter-entangling of thesheet of lyocell fibers and optional wood pulp fibers with can be doneby well-known means, commonly referred to as hydroentangling orspunlacing. The lyocell fibers have a length no less than 8 mm,preferably 8 to 100 mm, and most preferably 8 mm to 40 mm. In apreferred embodiment, the lyocell on the open face has a fiber lengthgreater than 18 mm, which provides both good coverage and stability forthe structure.

The lyocell fibers of the cellulosic nonwoven sheet can also be in theform of continuous filaments, especially if they are hydraulicallyentangled with wood pulp fiber, stabilizing the sheet.

The basis weight of the lyocell fiber web is typically from about 0.5 to5.0 ounces per square yard (ozsy) (about 17-170 grams per square meter,or gsm), more particularly in the range of about 1-3 ozsy (34-100 gsm).An embodiment uses a 100% lyocell nonwoven sheet having a basis weightof 1.6 ozsy (54 gsm).

The integrated nonwoven sheet 30 comprises an outer sublayer of woodpulp fibers integrated with an inner sublayer of textile fibers, and hasa weight ratio of wood pulp fibers to textile fibers of about 1:3 toabout 3:1. Typically, the content of the wood pulp fibers is about25-75% by weight, and the content of the textile fibers is about 25-75%by weight. Other integrated nonwoven sheets can comprise a weight ratioof wood pulp fibers to textile fibers of at least 1:2, for example, atleast 1:1, and at least 2:1, and up to about 2:1, for example, up toabout 1:1, and up to about 1:2.

The basis weight of the composite stitchbonded fabric is typically fromabout 2 to 10 ounces per square yard (ozsy) (about 70-340 grams persquare meter, or gsm), for a composite stitchbonded fabric having athickness of about 1 mm to 5 mm. A typical embodiment of the compositestitchbonded fabric has basis weight of about 4.6 ozsy (156 gsm).

In one embodiment, the textile fibers can comprise continuous orstaple-length fibers. In another embodiment the textile fibers of thecomposite nonwoven sheet 30 comprise polyester fibers, describedhereinafter in detail. In an alternative embodiment, the textile fibersof the composite nonwoven sheet 30 can comprise lyocell fibers,substantially as described herein above, instead of polyester fibers, orin a combination or fiber mixture with polyester fibers.

In another alternative embodiment, the inner sublayer of textile fiberscan comprise PLA fibers, alone or in a combination or fiber mixture withpolyester fibers and/or lyocell fibers. The PLA fibers have a length noless than 5 mm, preferably 8 to 100 mm, and most preferably 8 mm to 40mm.

In one embodiment, the integrated nonwoven sheet 30 is made byentangling continuous polyester fibers comprised in a continuousfilament polyester spunbond/spunmelt fabric (polyester fabric) 32, withsublayer 34 web comprising wood pulp fibers. The inner surface of theinner sublayer of the composite nonwoven sheet 30, facing the cellulosicnonwoven sheet 20, is comprised of the polyester fabric sublayer 32. Theouter surface of the integrated nonwoven sheet 30 is comprised of thewood pulp web sublayer 34.

The inter-entangling of the wood pulp fibers of sublayer 34 with thepolyester fibers (or other textile fibers) of sublayer 32 can be done bywell-known means, including hydroentangling as described, for example,in U.S. Pat. No. 6,516,502, the disclosure of which is incorporated byreference. The sublayer 34 of wood pulp fibers can be produced using anair-lay machine inline, or offline with prebonding via hydroentangling,or it can be introduced as a paper produced in a wet-lay machine. Thelayer 34 can contain 100% wood pulp fibers, or a blend of wood pulpfibers with other natural cellulosic fibers, for example cotton, flax,hemp, jute, and ramie. The wood pulp layer 34 and the polyester fabric32 have an intermediate interface 28, across which wood pulp fibers fromthe web layer 34 can blend into and with the polyester fibers of thepolyester fabric 32, and the polyester fibers of the polyester fabric 32can blend into and with the wood pulp fibers from the web layer 34. Inother words the intermediate interface 28 can comprise a gradient of ablend of polyester fibers and wood pulp fibers. Processes forhydroentangling the respective fibers of two or more overlapping fibersheets are well-known, and include those described in U.S. Pat. No.9,394,637, and US Patent Publications 2016/0228337 and 2017/0203542, thedisclosures of which are incorporated by reference in their entirety.

The basis weight of the integrated nonwoven sheet is typically fromabout 0.5 to 5.0 ounces per square yard (ozsy) (about 17-170 grams persquare meter, or gsm), more particularly in the range of about 2-4 ozsy(68-135 gsm). An embodiment can use a 55/45 weight blend of wood pulpfibers and polyester fibers, having a basis weight of 2.6 ozsy (88 gsm).

The length of the wood pulp fibers is preferably at least about 1.5 mm,and typically no more than about 5 mm, and preferably about 2.5 mm to3.5 mm, with a diameter ranging from about 15 microns to about 40microns. Other natural cellulose fiber may be employed in combinationwith wood pulp fiber, such as pulped rayon fibers. In one embodiment awood pulp can be a southern pine Kraft or obtained from a sulfitepulping process. Mixtures of natural cellulose fibers may be used. Thenatural cellulose fibers may be pulped in hammermills to form a mixtureof fine individual loose fibers. In general, very fine powderized fibersare avoided, or kept at a very low percentage level.

The length of the polyester (textile) fibers is no less than 5 mm, andtypically are at least 8 mm, for example, at least 10 mm, for example,at least 15 mm, at least 20 mm, and at least 25 mm, and up to about 50mm or more, for example, up to about 40 mm, up to about 35 mm, and up toabout 25 mm. They can also be continuous filaments.

In an embodiment of the invention, the composite stitchbonded fabric canoptionally comprise one or more additional films or fibrous sheetlayers, for example, a third nonwoven sheet. The material of the fibersor the film of the third nonwoven sheet can be selected from amongpolyester and its co-polymers, and polypropylene, for example,polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT),polycyclohexane dimethylene terephthalate (PCT), polybutyleneterephthalate (PBT), and PET modified with polyethylene glycol (PEG). Inan alternative embodiment, the third nonwoven sheet can includecellulosic fibers, selected from one or more of lyocell fibers, PLAfibers, and rayon fibers. In a preferred embodiment, the third nonwovenlayer comprises polyester fibers, and is disposed between the cellulosicnonwoven sheet and the integrated nonwoven sheet, before stitching.

Suitable bulkable or shrinkable yarns typically comprise a plurality offilaments. They may comprise a one or combination of a textured, DTY(draw textured yarn), SDY (spun drawn yarn), POY (partially orientedyarn), FOY (fully oriented yarn), threads or yarns of a polymericmaterial. The polymeric material can include polyester, nylon, andfunctionally equivalent polymers, and composite yarns can be anelastomeric yarn (for example, elastomerics such as Lastol-P® availablefrom Dow's XLA generic or high temperature Lycra®) in an extended state,wrapped with inelastic nylon or polyester.

Bulking of the bulkable yarns (a) increases entanglement of the yarnswith the fibrous material of the cellulosic nonwoven sheets 20 and theintegrated nonwoven sheet 30, and enhances the fabric stability anddurability, and (b) causes gathering of the towel-sized fabric 80, whichresults in a stitchbonded washable towel 90 with a softer hand, improveddrape, and decreased stiffness.

Conventional nonwoven fabrics containing a sheet of staple fibers, andespecially of polyester fibers, have the tendency to abrade or pill withwashing and wearing of the fabric. Conventional means to minimizeabrading and pilling have included bonding of the polyester fibers withresins or through thermal stabilization. Without being bound by anyparticular theory, the present invention places the textile fibersublayer 32 of polyester fibers of the integrated nonwoven sheet 30,between the sublayer 34 of wood pulp fibers, to which the textile fibersublayer 32 is hydroentangled, and the cellulosic nonwoven sheet 20 ofcellulosic fibers, which protects the polyester fibers from exposure atthe outer surface(s) of the composite stitchbonded fabric 10 to minimizeand prevent abrading and pilling of the polyester fibers in the sublayer32.

Further, the entangling of the polyester fibers of the textile fibersublayer 32 with the wood pulp fibers of sublayer 34 is believed tostabilize and anchor the wood pulp fibers. The parallel, tight rows ofyarn underlaps 60 overlay the wood pulp fibers on the technical back 18of the fabric 10, confining and protecting the exposed wood pulp fibers.The combination of the parallel, tight rows or wales 70 of stitchingyarns, along with the entangling of the bulked yarns with the polyesterfibers within sublayer 32 protects and maintains the structure of thefabric through multiple industrial washings of the towel.

Method for Making a Composite Stitchbonded Fabric

The present invention also includes a method for making the compositestitchbonded fabric.

First, a cellulosic nonwoven sheet and an integrated nonwoven sheet areprovided for overlaying and stitching. The cellulosic nonwoven sheetcomprises the nonwoven layer of cellulosic fibers, typically lyocellstaple fibers. The integrated nonwoven sheet comprises the outersublayer of wood pulp fibers and the inner sublayer of textile fibers,for example, polyester fibers, with the wood pulp fibers heavilyentangled with the textile fibers.

The cellulosic nonwoven sheet is placed over the inner surface of theintegrated nonwoven sheet, typically by overlapping the inner sublayerof the integrated nonwoven sheet, by well-known means.

The overlapping sheets are stitched together into a nonwoven fabric. Inone embodiment, the stitch bonding is made in a stitching pattern thatcan include, but not be limited to, a Tricot pattern, or a 3- or 4-rowAtlas pattern. The row spacing between wales 70 in the cross-machine XDdirection, commonly referred to as “gauge”, is in the range of 5 to 25rows per inch (2 to 10 rows per centimeter), while the course stitchspacing in the course or machine MD direction (commonly referred to as“course per inch” or “CPI”, is in the range of 5 to 38 stitches per inch(2 to 15 stitches per centimeter). In a preferred embodiment, the rowspacing between wales is about 14 or more rows per inch (6 rows percentimeter), while the course stitch spacing is about 7 or more stitchesper inch (3 stitches per centimeter).

The stitching patterns in a stitchbonding machine mirror those of a warpknitting machine. Examples of stitching patterns are illustrated in“Investigation of the Two-Bar Warp-Knitted Fabric Structure Effect onLuster Value”, Saeed Ajeli, Journal of Engineered Fibers and Fabrics,Vol 9, Issue 2, 2014, pp 32-37, the disclosure of which is incorporatedby reference. Stitching techniques and parameters can also be used asdescribed in U.S. Pat. Nos. 5,308,673 and 5,902,757, the disclosures ofwhich are incorporated by reference.

The selection of the yarns for the stitching process has an effect onthe properties of the stitchbonded fabric and, following anypost-treatment and shrinkage control, the properties of the finishedwashable towel. In an embodiment of the invention, the yarns areselected to provide a shrinkage performance from a post-treating processof at least 16%, and typically at least 18%, and more typically at least20%, in the machine direction (MD) and a growth of less than 10% in thecross-machine direction (XD) (See FIG. 1), to convert the compositestitchbonded fabric into a stitchbonded washable towel with goodappearance and hand.

While both a nylon yarn and a polyester yarn will shrink when exposed toheat in the post-treating process, the extent and endpoint of shrinkagebetween polyester and nylon can differ. When using polyester in bothbars, the degree of shrinkage is less than desired, and may create atowel with the desired aesthetic. But when using nylon in both bars, theshrinkage may continue at a rate greater than desired, at eachsubsequent laundering step of the towel, defined as a net area shrinkageof more than 8% after 25 washes.

Consequently, using one bar of nylon and one bar of polyester, acontrollable shrinkage of the composite stitchbonded fabrics produces astitchbonded washable towel with good properties. In one embodiment, thefront-bar yarn can comprise a partially-oriented nylon yarn, while theback-bar yarn comprises a partially-oriented polyester yarn. In anotherembodiment, the front-bar yarn can comprise a partially-orientedpolyester yarn, while the back-bar yarn comprises a partially-orientednylon yarn.

When combining the two or more nonwoven sheets or substrates, eachgreater than 1.0 ounce per square yard, using a stitch-bonding machinewith a gauge 14 or greater, and 7 courses per inch or more effectiveshrinkage control is achieved. Good shrinkage control is considered as anet area shrinkage of less than 8%, after a 25-wash test.

While other synthetic yarns such as polypropylene can provide anacceptable stitchbond structure, the increased oleophilic contentcontributed by such synthetic yarns to the fabric increases thedifficulty with which cooking oils can be removed from the structure insubsequent washing and cleaning.

Post-Treatment and Sizing

The present invention also includes a method for post-treating atowel-sized stitchbonded fabric into a stitchbonded washable towel. Moreparticularly, the post-treatment process or method includes a treatmentof the plurality of towel-sized fabric units, after they have beenstitchbonded, to form a plurality of washable, stitchbonded towels.

The composite stitchbonded fabric is cut to towel-size and stitched orsealed along at least a portion of the periphery, such as along oneside, opposed sideds, and both opposed sides, to form a stable boundary.A preferred method simultaneously cuts and bonds (forms the boundary)using an ultrasonic device. In one embodiment, the stitchbonded fabric10 can be slit into the individual towel units 80 and stitched along theperiphery 84 with a stitching yarn. In an alternative embodiment, apattern of outer boundary regions 82 of the stitchbonded fabric 10 canbe ultrasonically sealed in the pattern, and slit within the outerboundary regions 82 into individual towel units 80. With ultrasonicslitting, the towel-sized fabrics 80 may can is cut and sealed in onestep.

The method further comprises the steps of placing a plurality of thetowel-sized fabric units 80 into a drum of a laundering apparatus, suchas an industrial rotary washer. The plurality of the towel-sized fabricunits are exposed for a controlled amount of time to a heated aqueoussolution having a controlled temperature sufficient to cause the nylonyarns and the polyester yarns to shrink to a desired extent. Physicalagitation of the towel-sized fabrics aids in the sizing process. Thefabric units are exposed for the time sufficient to cause gathering ofthe fabric into the towel. The ratio of water solution to the weight oftowel-sized fabric units (stitchbonded fabrics) is typically between 2:1to about 10:1, depending on the type of machine and mechanicalparameters. The time sufficient to cause the nylon yarns and thepolyester yarn to shrink is from about 5 minutes to about one hour,again depending on the type of machine and mechanical parameters. Forexample, a typical time can be time of 1 minute to 20 minutes, at atemperature including and between 150 degrees F. to 205 degrees F. (66to 96 degrees C.). Preferably, the temperature of the heated aqueoussolution at which the towel-sized fabric units are exposed, is lowerthan a temperature at which the nylon and polyester filaments becomefully fixed. This allows the yarns of the stitchbonded towel to havesome degree or amount of stretch and “give” (flexibility) aftertreatment, and during subsequent uses and wash cycles. The temperatureof the heated aqueous solution is well over the conventional industriallaundering wash water temperature, or the temperature to be employed forsubsequent laundering of the towels of the present invention.

After the exposure of the fabric units to the heated aqueous solution,the fabric units are drained and rinsed in one or more lower-temperaturebaths, to cool the treated and pre-shrunk towels to a suitabletemperature for unloading of the machine and mitigating any creasingthat may occur if the heated towels are left uncooled.

In one embodiment, the heated aqueous solution has a temperature ofabout 125 to 200 degrees F. (52 to 93 degrees C.). Solution temperaturesin this range are sufficient to effect partial curing of the polymericyarns, but less than a temperature at which the polymeric yarns canbecome fully cured. Temperatures at or above 225 degrees F. (107 degreesC.) generally should be avoided for most polymer yarns. Typically, thetime sufficient to cause the nylon yarn and the polyester yarn to shrinkis from about 5 minutes to about one hour. In combination, depending onthe polymer of the yarn, the temperature of the heated aqueous solution,and the time duration for pre-treatment, a towel having any desireddegree of polymer curing, and hence shrinkage and gathering, andextensibility during use.

In another embodiment of the invention, the heated aqueous solution cancomprise a soil release polymer agent, preferably at an active level ofabout 0.03% to 3.0% by weight of the dry towel-sized fabric units, andin a typical embodiment, about 0.1 to 0.6% by weight of the drytowel-sized fabric units. A suitable soil release polymer agent providesprotection from the re-deposition of soils in the first and early washcycles onto the fibers and fabric, including the polyester, nylon, andcellulosic fibers, of the stitchbonded washable towel. The soil releasepolymer included in the heated aqueous solution provides to thefreshly-manufactured towel a resistance to redeposition of accumulatedsoils in the washing solution, typically from other soiled fabrics in awashing cycle, onto the stitchbonded towel, including onto thesubstantial amount of nylon and polyester stitching yarn in the washabletowel.

Examples of suitable soil release polymers (SRP) agents are lowmolecular weight, hydrophilic polyester polymers. These types ofcompounds are used in the textile industry as semi-permanent soilrelease compounds on polyester fabrics, as oil scavengers in scouringand dyeing of synthetic fiber textile fabrics (especially polyesterknits), and as softeners and lubricants for polyester textile fabrics.Such SRP agents are known to be used in laundry detergent formulations,where their effect in assisting soil removal is expected to build upslowly over repeated washings.

The SRP agents of the present invention can include nonionic soilrelease agents having oxyethylene hydrophiles, for example, thecondensation polymers of polyethylene glycol and/or ethylene oxideaddition products of acids, amines, phenols and alcohols which may bemonofunctional or polyfunctional, together with binder molecules capableof reacting with the hydroxyl groups of compounds with a poly(oxyalkylene) chain, for example, organic acids and esters, isocyanates,compounds with N-methyl and N-methoxy groups, bisepoxides, etc.Particularly useful are the condensation products of dimethylterephthalate, ethylene glycol and polyethylene glycol (ethoxylatedpolyester) and ethoxylated polyamides, especially ethoxylated polyestersand polyamides having a molecular weight of at least 500, as well assoil release agents described in the following patents, the disclosuresof which are incorporated herein by reference: U.S. Pat. Nos. 3,416,952,3,660,010, 3,676,052, 3,981,807, 3,625,754, 4,014,857, 4,207,071,4,290,765, 4,068,035 and 4,937,277. Combinations of anionic soil releaseagents with oxyethylene hydrophile condensates, such as are generallyreferred to as sulfonated ethoxylated polyesters and soil release agentsare disclosed in the following patents: U.S. Pat. Nos. 3,649,165,4,073,993, and 4,427,557, the disclosures of which are incorporatedherein by reference. Additional hydrophilic treatments may be found inU.S. Pat. No. 7,012,033, incorporated herein by reference.

A non-limiting example of a soil release polymer is Pomoco 5962 (CASNumber 9016-88-0), available from Piedmont Chemical Industries. Thispolymer has been found to be surprisingly effective in preventingre-deposition soiling, including on the cellulosic portions of thenonwoven washable towels of the invention, showing a significantimprovement in the cleanliness, whiteness, and residual odor, whentowels treated this way are washed conventionally with cotton bartowels.

In another aspect of the invention, the use of the hydrophilic SRP agentin a pre-treatment of the washable towel, effects a surface on thepolyester fibers and yarns that is more wettable by water, to improvethe absorbency and wicking performance of the nonwoven washable towel isnot impaired and is in some cases enhanced, relative to the washabletowel without SRP agent treatment or conventional bar towels. When thepre-treated washable towel has been dried following the pre-treatmentwith SRP agent, the dried towel is softer and more flexible, and lesspaper-like, than conventional towels having comparable quantities andtypes of cellulosic fibers.

In another embodiment of the method, a temperature of the heated aqueoussolution containing the SRP agent is maintained in a range between about175 and 185 degrees F. (79 and 85 degrees C.), in order to partially fixa portion of the SRP agent in the heated aqueous solution to the fibersand yarns of the washable towel, where the affixed SRP agent remainsthrough the rinse and drying cycles. The resulting washable towel isthen used in ordinary cleaning duty, and when washed for the first timewith other soiled towels, the residual affixed SRP agent improves therelease of accumulated soils and stains, and helps prevent re-depositionof soils and stains from the wash solution onto the cleaned, washabletowel.

Without being bound by any particular theory, it is believed that thesoil release polymer agent that is applied to the fabric in thepre-treating process allows the SRP agent to be retained sufficiently tothe fabrics to serve as a barrier to staining under normal use. However,at the proper laundering conditions, including wash solution temperatureand washing agents, the retained SRP agents can be substantially removedfrom the fabrics in the subsequent wash process, to assist in freeingsoils from the towel surface and creating an enhanced cleaning effectunder less rigorous washing conditions.

Washable Towels

Employing the composite stitchbonded fabric and the post-treatingprocess described herein, the present invention provides a stitchbondedwashable towel. The towel comprises a gathered, cellulosic nonwovensheet along the technical front or face of the fabric, and a gathered,integrated nonwoven sheet along the technical back of the fabric. Thegathered component sheets of the stitchbonded washable towel areintegrated together with a multiplicity of stitching yarns comprisingoverlaps on the technical front and underlaps on the technical back, tofix and gather the cellulosic nonwoven face sheet to the integratednonwoven back sheet.

In another embodiment of the invention, the fibers or sheets of thestitchbonded washable towel further include soil release polymer coatedin the pre-treating process, onto the surfaces of at least one of, andtypically all of, the fibers.

In one embodiment, the stitchbonded fabric, and the stitchbondedwashable towel formed therefrom, has a density of between 150 and 300grams per square meter, creating a light-weight towel with goodabsorption and physical durability. In specific embodiments, thestitchbonded washable towel of the invention can be specificallydescribed in terms of durability of the towel. The desired durability istypically established based on, among other things, the applicationwhere the towel is intended to be used or the number of washes thefabric should be capable of sustaining. For example, in certainembodiments of the invention, the nonwoven fabric will be capable ofsustaining at least 1 wash, at least 2 washes, at least 3 washes, atleast 5 washes, at least 7 washes, at least 10 washes, at least 15washes, at least 20 washes, at least 25 washes, at least 30 washes, atleast 35 washes, at least 40 washes, at least 45 washes, or at least 50washes under temperature, detergent solution, bleaching, and abrasiveaction conditions according to AATCC (American Association of TextileChemists and Colorists) 61 wash test standard 4A for laundering. Thedurability of the towel can mean that the towel can continue to be usedin the intended application(s) and undergoes numerous washes with nosubstantial change in the structural integrity of the fabric of thetowel (no raveling and resistant to hole formation), maintaining itsstronger tensile strength, with little or no pilling on the surface ofthe towel, and without good hand and appearance, even under industriallaundering conditions. In another embodiment, the durable towelsuccessfully undergoes multiple washes, with the towel substantiallymaintaining the ability to continue to be used in the application(s) forwhich it was intended, even after undergoing one or more washes.

The stitchbonded washable towel preferably has an absorbency of aqueoussolutions of at least 400% by weight of the towel. Additionally, thetowel preferably has a stoll flat abrasion results of greater than 500cycles after 30 industrial washes as tested by ASTM D3886-99.

Preferably, the towel 90 has durability to commercial laundering. After30 industrial washes, the nonwoven towel preferably has a tongue tearstrength of at least 10 lb-f as tested by ASTM2261. Additionally, thetowel 90 preferably has a grab tensile strength of at least 50 lb-f astested by ASTM D5034, and a sled friction of greater than 0.15 as testedby ASTM D1894 (friction is desired for picking up kitchen objects suchas pots and pans) after 30 industrial washes. In one embodiment, thetowel 90 has a tongue tear of at least 10 lb-f in the warp and weftdirections after being subjected to a chlorine test consisting of aseries of 2 industrial washes and dryings and an overnight soaking in a5% bleach solution repeated 5 times. Additionally, the towel 90preferably has a tensile strength of at least 50 lb-f (pound force) inthe warp and weft directions after the after the chlorine test washes.

The stitchbonded washable towels of the invention may be used as towels,sport towels, salon towels, automotive and transportation wash towels,retail bath towels, cabinet roll towels, bar-mops, restaurant cleaningtowels, industrial and commercial cleaning towels, table skirting, tablepads, and pharmaceutical and chemical absorbent.

Washable towels made in accordance with the present invention providebetter performance in cleaning and absorbing, with a lighter weight oftowel. The towel provides a better or cleaner surface (less linting),while absorbing more liquid due to better absorbency and wicking,typically absorbing about twice as much water per weight of towelcompared to terry towels.

The washable towel also can also be used to clean the “front of thehouse”, including tables, glassware, windows, and bar tops. Thiseliminates any need for a second type of towel, for example, adisposable towel or microfiber towel, for cleaning these surfaces. Andthe washable towel provides these benefits despite its light weight thana conventional towel, which improves the laundering efficiency in alaundry plant. The lower towel weight allows more towels per load to bewashed and dried per cycle (about 30% to 60% more), resulting in lowerdirect cleaning cost per towel, and higher productivity of the plant.

EXAMPLES

A. Stitchbonded Fabric Making

A continuous nonwoven sheet of 100% lyocell fibers (sourced from Norfin(USA) LLC and selected from among a 1.6 oz product reference 02440, or a2.4 oz product reference 02441) was overlaid onto an inner face of acontinuous integrated nonwoven sheet consisting of an outer nonwovenlayer of wood pulp fibers and an inner nonwoven layer of polyesterfibers that have been heavily entangled with the wood pulp fibers(sourced from Jacob Holm and selected from 2.0 oz product reference8801, 2.6 oz product reference 8890, and 3.6 oz product reference 8805).The overlapping nonwoven sheets were stitched together into astitchbonded nonwoven fabric, using a two-bar stitching systemcomprising a front-bar yarn of polyester textured, bulkable filamentyarn (75 den/36), and back-bar yarn of textured, bulkable nylon filamentyarn (70 den/40). The stitching pattern was selected from among a chainor pillar pattern, a Tricot pattern, or a 3- or 4-Row Atlas pattern,with a row spacing or gauge of about 14 rows per inch, and a stitchspacing or CPI of about 7 stitches per inch. The fabric was slit intotowel-size fabric units, and stabilized at the boundary.

B. Towel Shrinkage and Post-Treatment

In a standard industrial laundry machine, the wash drum was loaded witha desired weight of dry stitchbonded, towel-sized fabric units. Themachine was operated throughout at the rotational speed and direction asdictated by the machine. Water was added into the machine to a desiredlevel, and an 0.6% of Pomoco 5962 SRP agent, by weight of the drystitchbonded towel-sized fabrics, was added to the water solution. Thewater solution was then heated to 185 degrees F. (85 degrees C.) andheld for 15 minutes with agitation.

The heated water solution was drained and the machine filled to thedesired level with warm water (for example, including and between120-140 degrees F. (49-60 degrees C.)) and held for 5 minutes withagitation.

The warm water was drained and the machine filled to the desired levelwith cold water (e.g., 70 degrees F. (21 degrees C.)). After fiveminutes, the cold water was drained and residual bulk water was removedfrom the wet load of towels by spinning.

The damp, pre-treated towels were removed from the drum and dried in atumble dryer.

It is intended that the scope of the present invention include allmodifications that incorporate its principal design features, and thatthe scope and limitations of the present invention are to be determinedby the scope of the appended claims and their equivalents. It alsoshould be understood, therefore, that the inventive concepts hereindescribed are interchangeable and/or they can be used together in stillother permutations of the present invention, and that othermodifications and substitutions will be apparent to those skilled in theart from the foregoing description of the preferred embodiments withoutdeparting from the spirit or scope of the present invention.

1.-31. (canceled)
 32. A stitchbonded washable towel that is durable tomultipole cycles of commercial laundering and use, comprising: i) agathered cellulosic nonwoven face sheet comprising a nonwoven layer ofcellulosic fibers; ii) a gathered integrated nonwoven back sheetcomprising an outer sublayer of wood pulp fibers and an inner sublayerof textile fibers that are heavily entangled with the wood pulp fibersof the outer sublayer, with the inner sublayer of textile fibersconfronting the gathered cellulosic nonwoven face sheet; and iii) amultiplicity of partially-extensible stitching yarns, which fix thegathered cellulosic nonwoven face sheet to the gathered integratednonwoven back sheet and cause the composite to gather, wherein thestitching yarns form a plurality of yarn overlaps on the face sheet andat least one set of the yarn underlaps on the back sheet that bridgeacross one or more stitched wales over the outer sublayer of wood pulpfibers.
 33. The stitchbonded washable towel according to claim 32,further including a soil release polymer coated onto the surfaces of atleast the textile.
 34. The stitchbonded washable towel according toclaim 32, wherein the cellulosic fibers of the gathered cellulosicnonwoven face sheet comprise lyocell fibers, and further comprises up toabout 75% wood pulp fibers by weight that have been inter-entangled withthe lyocell fibers.
 35. The stitchbonded washable towel according toclaim 33, wherein the soil release polymer comprises Pomoco
 5962. 36.The stitchbonded washable towel according to claim 32, wherein the yarnoverlaps comprise partially-oriented nylon and the yarn underlapscomprise partially-oriented polyester.
 37. The stitchbonded washabletowel according to claim 32, wherein the yarn overlaps comprisepartially-oriented polyester and the yarn underlaps comprisepartially-oriented nylon.
 38. The stitchbonded washable towel accordingto claim 32, wherein the integrated nonwoven sheet comprises about25-75% by weight wood pulp fibers and about 25-75% by weight polyesterfibers.
 39. The stitchbonded washable towel according to claim 32,wherein the cellulosic fibers of the cellulosic nonwoven sheet compriselyocell.
 40. The stitchbonded washable towel according to claim 39,wherein the cellulosic nonwoven sheet further comprises other cellulosicfibers selected from the group consisting of rayon, cotton, flax, hemp,jute and ramie, and a mixture or combination thereof.
 41. Thestitchbonded washable towel according to claim 32, wherein thepartially-extensible stitching yarn is selected from the groupconsisting of a partially-oriented polymeric material and an elastomericyarn component.
 42. The stitchbonded washable towel according to claim32, wherein the wherein the partially-oriented polymeric material isselected from the group consisting of partially-oriented polyester,partially-oriented nylon, and a combination or a mixture thereof. 43.The stitchbonded washable towel according to claim 32, further includinga gathered third sheet, disposed between the gathered cellulosicnonwoven face sheet and the gathered integrated nonwoven back sheet. 44.The stitchbonded washable towel according to claim 43, wherein thegathered third sheet is a fibrous sheet.
 45. A method for making astitchbonded washable towel, comprising the steps of: a) providing acellulosic nonwoven sheet comprising a nonwoven layer of cellulosicfibers, the cellulosic fibers being selected from the group consistingof continuous lyocell filaments and staple-length cut lyocell fibers; b)providing an integrated nonwoven sheet comprising an outer sublayer ofwood pulp fibers and an inner sublayer of textile fibers, wherein thetextile fibers of the inner sublayer are highly entangled with the woodpulp fibers of the outer sublayer to form the integrated nonwoven sheet,with the inner sublayer of textile fibers providing an inner surface ofthe integrated nonwoven sheet; c) placing the cellulosic nonwoven sheetover the inner surface of the integrated nonwoven sheet; d) stitchingthe cellulosic nonwoven sheet to the integrated nonwoven sheet with oneor more stitching yarn to form a composite stitchbonded fabric,comprising forming the one or more stitching yarn as a plurality of yarnoverlaps on a technical front of the composite stitchbonded fabricaligned with the cellulosic nonwoven sheet, and the one or morestitching yarn as a plurality of yarn underlaps on a technical back ofthe composite stitchbonded fabric aligned with the wood pulp sublayer ofthe outer sublayer of the integrated nonwoven sheet, wherein at leastone of the yarn overlaps and the yarn underlaps comprises a shrinkableyarn, and at least one set of the yarn underlaps originate from onestitching bar, and bridges across one or more stitched wales over theouter sublayer of wood pulp fibers; e) forming the compositestitchbonded fabric into a plurality of fabric units having a size of atowel, and optionally forming a stabilized boundary region along aportion of a periphery of the fabric units; f) placing the fabric unitsinto a drum of a laundering apparatus; and g) exposing the fabric unitsto a heated aqueous solution having a temperature less than atemperature at which the shrinkable yarns become fully fixed, for aperiod of time sufficient to effect shrinkage and gathering of thefabric units into the stitchbonded washable towels.
 46. The methodaccording to claim 45, wherein the step of stitching with one or morestitching yarn comprises stitching with a first stitching yarncomprising a textured and bulkable nylon, and with a second stitchingyarn comprising a textured and bulkable polyester.
 47. The methodaccording to claim 45, wherein the heated aqueous solution has atemperature between about 125 and 200 degrees F.
 48. The methodaccording to claim 47, wherein the temperature is between about 175 and185 degrees F.
 49. The method according to claim 45 wherein the timesufficient is from about 5 minutes to about one hour.
 50. The methodaccording to claim 45, wherein the heated aqueous solution comprises asoil release polymer at a level of about 0.05% to 3.0% by weight of thedry towel-sized fabric units, and wherein the temperature of the heatedaqueous solution is in a range sufficient to at least partially fix thesoil release polymer to at least one of the wood pulp fibers and thelyocell fibers.
 51. The method according to claim 50, wherein thetemperature is from about 175 to 185 degrees F., and the soil releasepolymer comprises Pomoco 5962.